A sensor cover is a part for covering an antenna of a sensor and installed to protect a general antenna from collision, debris, and strong wind pressure. Accordingly, a sensor cover is required to have strength to be able to withstand wind pressure, friction with air, hail, and the like, weather resistance, lightness in weight, an excellent electromagnetic wave transmittance, and the like.
However, in some cases, there is a limitation in designing a sensor cover in terms of a design. An auto cruise control system refers to an apparatus in which when a driver operates a switch at a desired speed, a computer stores the vehicle speed to allow the driver to drive the vehicle without pressing an acceleration pedal. The auto cruise control system controls a distance between the vehicles as well as the vehicle speed, and a sensor installed in the system may detect the distance between the vehicles. A sensor for detecting the distance between the vehicles needs to be installed at the front of the vehicle, and a sensor cover capable of covering the antenna of the sensor is required aesthetically. In addition, the sensor cover for vehicles needs to be in harmony with the surrounding thereof.
FIG. 1 illustrates a perspective view showing an example of a vehicle in which a sensor is installed inside the front side. The sensor cover for vehicles may be provided in a front grille or at the rear side of an emblem, or may be the emblem itself. FIGS. 2 and 3 illustrate perspective views showing examples of the front grille provided with the sensor cover for vehicles. In FIG. 2, the sensor cover for vehicles is provided at the center of the front grille. In addition, in FIG. 3, the sensor cover for vehicles itself becomes the emblem. Generally, the front grille exhibits black and/or silver color. The emblem mostly exhibits the black and/or silver color. Accordingly, when the sensor cover for vehicles is made of transparent material in order to secure electromagnetic wave transmissivity, the sensor cover for vehicles is difficult to be in harmony with the surrounding thereof. Furthermore, it is not aesthetically good that the interior of the vehicle is shown through the transparent sensor cover. However, when the sensor cover for vehicles is made of the material exhibiting black or silver color, the sensor cover for vehicles is continuous with the front grille and/or the emblem therearound, but there is a problem of securing the electromagnetic wave transmissivity.
In the related art, indium (In) or tin (Sn), which are materials capable of transmitting the electromagnetic waves while exhibiting a metallic color and glossiness, were used as a sensor cover material. As the prior art related thereto, there is Japanese Patent Registration No. 3366299 (hereinafter referred to as Prior Art 1).